LEGO Profit Calculator
Enter what you paid, what it sells for, and where you're selling. Get your real net profit after fees and shipping — plus a straight buy, hold, or skip call.
Fees on this sale: $69
Strong flip — margin clears your costs with room to spare.
The sets nearing end-of-life right now, with my buy/hold/skip call — free.
Estimates only — marketplace fees change and resale values move. Not financial advice.
How the math works
No black box. Here's exactly what the tool does with your numbers.
- Fees = sell price × marketplace rate + flat fee
- Net profit = sell − buy − fees − shipping
- ROI % = net profit ÷ buy cost × 100
- Margin % = net profit ÷ sell price × 100
- Price / piece = buy cost ÷ piece count — the number LEGO investors judge a set on
LEGO flipping questions
How do you calculate profit on a LEGO set?
Net profit = resale price − what you paid − marketplace fees − shipping. Fees are the sell price times the marketplace rate plus any flat fee. ROI is net profit divided by your buy cost.
What are the marketplace fees for selling LEGO?
This calculator uses eBay 13.25% + $0.30, Amazon 15%, BrickLink 3%, Mercari 10%, and 0% for local or Facebook sales. These are referral fees that come off the sell price before profit. If you sell on Amazon FBA, enter your per-item fulfillment fee in the FBA field so it counts as a cost too; leave it $0 if you ship the set yourself.
What is a good ROI for flipping LEGO?
As a rule of thumb: 100%+ ROI is a strong flip (buy), 40–100% is thin but positive (hold for a deal), and under 40% usually gets eaten by fees and shipping (skip).
What is price per piece and why does it matter?
Price per piece is your buy cost divided by the set piece count. LEGO investors use it as a quick value gauge: under roughly 8–10 cents per piece is generally considered good.